Functional properties and molecular docking of different nanoparticles with ROS-sensitive phenylboronylated chitosan as the carrier

OBJECTIVE

To prepare chitosan-loaded nanoparticles (NPs) that enhance the oral bioavailability of puerarin (Pur) and render it responsive to reactive oxygen species (ROS).

SIGNIFICANCE

This research makes substantial progress towards the theory of intelligent drug delivery, offering a new reference for combining Pur with other natural medicinal active ingredients.

METHODS

The acylation reaction between chitosan and ROS-sensitive 3-carboxyphenylboronic acid (PBA) was used to synthesise ROS-sensitive phenylboronylated chitosan (PBACS). Subsequently, PBACS-PBA-Pur-NPs and PBACS-TPP-Pur-NPs were prepared via ion gelation after the addition of PBA and sodium tripolyphosphate(TPP), respectively. The physicochemical and functional properties of both NPs were compared, and their differences were preliminarily studied through molecular docking.

RESULTS

Reactive oxygen species-sensitive PBACS was successfully synthesised. Of the two NPs prepared, PBACS-TPP-Pur-NPs had a size of 127.2 ± 0.80 nm, polydispersity index (PDI) of 0.129 ± 0.0008, and an encapsulation rate of 95.75 ± 0.387 %, whereas PBACS-PBA-Pur-NPs had a size of 149.8 ± 0.1414 nm, PDI of 0.389 ± 0.0012, and an encapsulation rate of 91.77 ± 0.279 %. The micromorphology of the PBACS-TPP-Pur-NPs exhibited better physical properties. However, PBACS-PBA-Pur-NPs demonstrated a faster in vitro release and more significant in vitro anti-inflammatory effects. Pharmacokinetically, the AUC0-24, Tmax, and Cmax of PBACS-PBA-Pur-NPs were 3.485, 2.117, and 3.339 times higher, respectively, than those of Pur. The AUC0-24, Tmax, and Cmax of PBACS-TPP-Pur-NPs were 2.41, 1.33, and 2.03 times higher, respectively, than those of Pur. Molecular simulation revealed that the binding energy of PBACS-PBA-Pur -NPs was approximately -4.34 kcal/mol and that of PBACS-TPP-Pur-NPs was even lower, approximately -5.93 kcal/mol, suggesting that the NPs prepared with TPP are more densely packed than those designed with PBA, resulting in slower and reduced drug release.

CONCLUSION

The NPs constructed in this study effectively reduced inflammatory factors at the disease site, providing a theoretical and experimental basis for the application of nano drugs in inflammatory disease models. In addition, the molecular docking study of the two NPs offered insights into the relationship between the release and structure of subsequent nano drugs.

Theoretical calculations of the performance of Li7NbO6 and its doped Phases as solid electrolytes

Materials with Hexagonal Close Packed (HCP) anionic configuration contain promising lithium-ion conductors. In the HCP anionic structure, when the non-lithium cations occupy the octahedral sites (the important diffusion channels for lithium ions), it is not known whether the nature of fast lithium-ion diffusion will be retained. This work systematically studied the lithium-ion diffusion properties of Li7NbO6 as well as its doped phases on the basis of first-principles calculations. The calculation results show that the lithium-ion conductivity of Li7NbO6 is 0.008 mS cm-1 at room temperature, while the doped phase Li55Nb7WO48 with W6+ doping at the Nb sites possesses a higher lithium-ion conductivity of 0.28 mS cm-1 at room temperature and an activation energy of 0.34 eV. The lithium-ion diffusion mechanism in Li7NbO6 and its doped phase involves concerted migration; besides, they are poor conductors of electrons regardless of whether doping is applied. In addition, W6+ doping increases the reduction limit of the electrochemical window due to its strong oxidizing property; therefore, an artificial SEI film needs to be applied to reduce interfacial decomposition. The discovery and characterization of the new fast lithium-ion conductor Li55Nb7WO48 provide theoretical guidance for the development of new solid electrolytes.

Mindfulness and academic procrastination among Chinese adolescents: a moderated mediation model

Background

While previous studies have linked mindfulness to reduced academic procrastination, the mechanisms involved remain under-explored. This study deepens the understanding by investigating how learning vigor mediates the mindfulness and procrastination relationship, and how harsh parenting influences this mediation.

Methods

This study, adopting a positivist research approach, utilized a cross-sectional design. Data were collected from 800 students at three middle schools in Henan Province, China, through cluster random sampling. This approach yielded 800 questionnaires. The participants sequentially completed four questionnaires: the Mindfulness Attention Awareness Scale, the Utrecht Work Engagement Scale-Student, the Aitken Procrastination Inventory, and the Harsh Parenting Questionnaire. After removing 67 invalid questionnaires due to incomplete responses and patterned answers, a total of 733 valid questionnaires were obtained, with 53.3% girls and an average age of 13.12 years (SD = 1.01), leading to an effectiveness rate of 91.63%. Upon data collection, SPSS 26.0 software was used for correlation analysis, mediation analysis, and moderated mediation analysis to assess the relationships between variables.

Results

(1) Mindfulness negatively predicts academic procrastination; (2) Learning vigor serves as a mediator in the relationship between mindfulness and academic procrastination; and (3) Harsh parenting moderates the relationship between mindfulness and learning vigor. Specifically, the positive impact of mindfulness on learning vigor is more pronounced in individuals experiencing lower levels of harsh parenting compared to those with higher levels.

Conclusion

This study reveals that mindfulness significantly protects against academic procrastination in adolescents, with 52.27% of this effect mediated by increased learning vigor. Additionally, it shows that high levels of harsh parenting weaken mindfulness's positive impact on learning vigor, tempering its overall protective influence on procrastination. These insights, which apply Trait Activation Theory to educational psychology, not only deepen our understanding of the dynamics between mindfulness and procrastination but also have important implications for addressing academic procrastination in Chinese adolescents.

How do "words poorly expressed emotion" affect mental health? The mediating role of affect labelling effect

Previous studies have found that people with high negative emotional granularity(NEG) tend to have better health levels. It is generally believed that this is due to the selection and application of explicit emotion regulation strategies that affect mental health. However, no research has yet examined a more fundamental process, the role of affect labelling, an implicit emotion regulation strategy. This study focuses on the aforementioned issues and uses the experience sampling method to categorise participants into groups with high and low NEG. Using an affect labelling paradigm with ERP(event-related potential) technology, the study measures the effects of affect labelling in participants. Furthermore, it assesses the mental health levels of the participants through questionnaires to explore whether the affect labelling effect serves as a mediator between NEG and mental health. The results show that: (1) The high-NEG group exhibited significantly lower LPP wave amplitudes under affect labelling compared to under non-affect labelling, whereas the low-NEG group did not show significant differences. The results indicate that only the high-NEG group can produce the affect labelling effect. (2) The affect labelling effect mediates the relationship between NEG and mental health, meaning that NEG predicts mental health through the affect labelling effect.

Raspberry-liked Pickering emulsions based inulin microparticles for enhanced antibacterial performance of essential oils

Pickering emulsions seem to be an effective strategy for encapsulation and stabilization of essential oils. In this work, a novel raspberry-liked Pickering emulsion (RPE) loading Mosla chinensis 'Jiangxiangru' essential oil (MJO) was successfully engineered by using ethyl lauroyl arginate (ELA) decorated nanosilica (ELA-NS) as particles emulsifier. And the ELA-NS-stabilized MJO Pickering emulsion (MJO-RPE) was further prepared into inulin-based microparticles (MJO-RPE-IMP) by spray-drying, using inulin as matrix formers. The concentration of ELA-NS could affect the formation and stabilization of MJO-RPE, and the colloidal behavior of ELA-NS could be modulated at the interfaces with concentration of ELA, thus providing unique role on stabilization of MJO-RPE. The results indicated that the MJO-RPE stabilized ELA-NS with 2 % NS modified by 0.1 % ELA had long-term stability. MJO-RPE exhibited a raspberry-liked morphology on the surface, attributed to ELA-NS covered in the droplet surface. The inulin-based matrix formers could effectively prevent MJO-RPE from agglomeration or destruction during spray-drying, and 100 % concentration of inulin based microparticles formed large composite particles with high loading capacity (98.54 ± 1.11 %) and exhibited superior thermal stability and redispersibility of MJO-RPE. The MJO-RPE exhibited strong antibacterial efficacy against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), owing to the adhesion to bacterial membrane dependent on the raspberry-liked surface of MJO-RPE, whose minimum inhibitory concentration (MIC) of the above three bacteria were (0.3, 0.45, and 1.2 μL/mL), respectively, lower than those (0.45, 0.6 and 1.2 μL/mL) of MJO. Therefore, the Pickering emulsion composite microparticles seemed to be a promising strategy for enhancing the stability and antibacterial activity of MJO.

Fabrication and in vitro/vivo evaluation of quercetin nanocrystals stabilized by glycyrrhizic acid for liver targeted drug delivery

The purpose of this study was to design novel drug nanocrystals (NCs) stabilized by glycyrrhizic acid (GL) for achieving liver targeted drug delivery due to the presence of GL receptor in the hepatocytes. Quercetin (QT) exhibits good pharmacological activities for the treatment of liver diseases, including liver steatosis, fatty hepatitis, liver fibrosis, and liver cancer. It was selected as a model drug owing to its poor water solubility. QT NCs stabilized by GL (QT-NCs/GL) were fabricated by wet media milling technique and systemically evaluated. QT-NCs stabilized by poloxamer 188 (QT-NCs/P188) were prepared as a reference for comparison of in vitro and in vivo performance with QT-NCs/GL. QT-NCs/GL and QT-NCs/P188 with similar particle size around 130 nm were successfully fabricated by wet media milling technique. Both of QT-NCs/GL and QT-NCs/P188 showed irregular particles and short rods under SEM. XRPD revealed that QT-NCs/GL and QT-NCs/P188 remained in crystalline state with reduced crystallinity. QT-NCs/GL and QT-NCs/P188 exhibited significant solubility increase and drug release improvement of QT as compared to raw QT. No significant difference for the plasma concentration-time curves and pharmacokinetic parameters of QT were found following intravenous administration of QT-NCs/GL and QT-NCs/P188. However, a significantly higher liver distribution of QT following intravenous administration of QT-NCs/GL was observed in comparison to QT-NCs/P188, indicating QT-NCs stabilized by GL could achieve liver targeted delivery of QT. It could be concluded that GL used as stabilizer of QT NCs have a great potential for liver targeted drug delivery.

Rubusoside As a Multifunctional Stabilizer for Novel Nanocrystal-Based Solid Dispersions with a High Drug Loading: A Case Study

The oral bioavailability of poorly soluble drugs has always been the focus of pharmaceutical researchers. We innovatively combined nanocrystal technology and solid dispersion technology to prepare novel nanocrystalline solid dispersions (NCSDs), which enable both the solidification and redispersion of nanocrystals, offering a promising new pathway for oral delivery of insoluble Chinese medicine ingredients. The rubusoside (Rub) was first used as the multifunctional stabilizer of novel apigenin nanocrystal-based solid dispersions (AP-NSD), improving the in vitro solubilization rate of the insoluble drug apigenin(AP). AP-NSD has been produced using a combination of homogenisation and spray-drying technology. The effects of stabilizer type and concentration on AP nanosuspensions (AP-NS) particles, span, and zeta potential were studied. And the effects of different types of protective agents on the yield and redispersibility of AP-NSD were also studied. Furthermore, AP-NSD was characterized by infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD). Solubility was used to assess the in vitro dissolution of AP-NSD relative to APIs and amorphous solid dispersions (AP-ASD), and AP-ASD was prepared by the solvent method. The results showed that 20% Rub stabilized AP-NSD exhibited high drug-loading and good redispersibility and stability, and higher in vitro dissolution rate, which may be related to the presence of Rub on surface of drug. Therefore provides a natural and safe option for the development of formulations for insoluble drugs.

Pore engineering of micro/mesoporous nanomaterials for encapsulation, controlled release and variegated applications of essential oils

Essential oils have become increasingly popular in fields of medical, food and agriculture, owing to their strongly antimicrobial, anti-inflammation and antioxidant effects, greatly meeting demand from consumers for healthy and safe natural products. However, the easy volatility and/or chemical instability of active ingredients of essential oils (EAIs) can result in the loss of activity before realizing their functions, which have greatly hindered the widely applications of EAIs. As an emerging trend, micro/mesoporous nanomaterials (MNs) have drawn great attention for encapsulation and controlled release of EAIs, owing to their tunable pore structural characteristics. In this review, we briefly discuss the recent advances of MNs that widely used in the controlled release of EAIs, including zeolites, metal-organic frameworks (MOFs), mesoporous silica nanomaterials (MSNs), and provide a comprehensive summary focusing on the pore engineering strategies of MNs that affect their controlled-release or triggered-release for EAIs, including tailorable pore structure properties (e.g., pore size, pore surface area, pore volume, pore geometry, and framework compositions) and surface properties (surface modification and surface functionalization). Finally, the variegated applications and potential challenges are also given for MNs based delivery strategies for EAIs in the fields of healthcare, food and agriculture. These will provide considerable instructions for the rational design of MNs for controlled release of EAIs.

[The comparison between endoscopic and surgical treatment of delayed iatrogenic bile duct injury by propensity score matching]

Objective: To compare the safety and clinical efficacy of endoscopic and surgical treatment of patients with delayed iatrogenic bile duct injury (DBDI) with severity (SG) grade 1 to 2. Methods: The clinical data of 129 patients with SG grade 1 to 2 DBDI who received endoscopic or surgical treatment in the First Hospital of Lanzhou University from November 2007 to November 2021 were retrospectively collected. There were 46 males and 83 females,aged (M(IQR)) 54(22)years(range: 21 to 82 years). The baseline data of the two groups were matched 1∶1 by propensity score matching(caliper value was 0.2). Independent sample t test,rank sum test,χ2 test or Fisher exact probability test were used to analyze the data of the two matched groups. Results: There were 48 patients in each of the endoscopic treatment and surgical groups after matching,and there was no difference in general information between the two groups(both P>0.05). The bile duct injury-repair interval and intraoperative anesthesia complications were not statistically significant between the two groups after matching(all P>0.05). Compared with the surgical group, patients in the endoscopic treatment group had significantly shorter operative time(50 (30) minutes vs. 185 (100) minutes, Z=7.675,P<0.01) and postoperative hospital stay(5 (5) days vs. 12 (7) days, Z=5.848, P<0.01).For safety,there was no statistical difference in the incidence of immediate postoperative complications between the two groups with Clavien-Dindo classification of surgical complications<Ⅲ;the incidence of serious postoperative complications (Clavien-Dindo classification of surgical complications≥Ⅲ) was significantly higher in the surgical group than in the endoscopic treatment group(P=0.012). The incidence of long-term postoperative complications was not statistically different between the two groups(28.1% vs. 20.7%,P=0.562). In terms of efficacy,the postoperative liver function indexes of patients in both groups improved significantly compared with the preoperative period and returned to normal or near normal levels; the postoperative infection indexes of both groups showed an increasing trend,but were within the normal range. Of the 96 patients in both groups,61 obtained follow-up,and the follow-up time was (89.4±48.0)months(range: 3 to 165 months),and there was no statistical difference between the two groups(P=0.079). The probability of excellent long-term follow-up (78.1% vs. 86.2%) was not statistically different between the two groups(P=0.412).In patients with Strasberg-Bismuth type E1,the probability of excellent long-term follow-up was higher in the endoscopic treatment group compared with the surgical group(13/14 vs. 2/5,P=0.037). Conclusions: For DBDI patients with SG grade 1 to 2 and bile duct continuity,endoscopy can be used as the first deterministic treatment. The advantages of endoscopic therapy compared to surgery are the lower incidence of postoperative serious complications,and the shorter duration of surgery and postoperative hospital stay.

Powering mesoporous silica nanoparticles into bioactive nanoplatforms for antibacterial therapies: strategies and challenges

Bacterial infection has been a major threat to worldwide human health, in particular with the ever-increasing level of antimicrobial resistance. Given the complex microenvironment of bacterial infections, conventional use of antibiotics typically renders a low efficacy in infection control, thus calling for novel strategies for effective antibacterial therapies. As an excellent candidate for antibiotics delivery, mesoporous silica nanoparticles (MSNs) demonstrate unique physicochemical advantages in antibacterial therapies. Beyond the delivery capability, extensive efforts have been devoted in engineering MSNs to be bioactive to further synergize the therapeutic effect in infection control. In this review, we critically reviewed the essential properties of MSNs that benefit their antibacterial application, followed by a themed summary of strategies in manipulating MSNs into bioactive nanoplatforms for enhanced antibacterial therapies. The chemically functionalized platform, photo-synergized platform, physical antibacterial platform and targeting-directed platform are introduced in details, where the clinical translation challenges of these MSNs-based antibacterial nanoplatforms are briefly discussed afterwards. This review provides critical information of the emerging trend in turning bioinert MSNs into bioactive antibacterial agents, paving the way to inspire and translate novel MSNs-based nanotherapies in combating bacterial infection diseases.

Alexithymia and Internet Addiction in Children: Meaning in Life as Mediator and Reciprocal Filial Piety as Moderator

Purpose

To explore the psychological mechanism between alexithymia and Internet addiction, the present study constructed a moderated mediation model based on the problem behavior theory.

Methods

A total of 899 middle school students (Mage=13.95, SD=1.10) were surveyed using the 20-item Toronto-alexithymia-scale, meaning in life questionnaire, dual filial piety scale, and Internet addiction disorder diagnostic scale.

Results

First, alexithymia was significantly negatively correlated with meaning in life and reciprocal filial piety, and positively correlated with Internet addiction; meaning in life was significantly positively correlated with reciprocal filial piety, and negatively correlated with Internet addiction; reciprocal filial piety was significantly positively correlated with authoritarian filial piety, and negatively correlated with Internet addiction. Second, alexithymia could not only directly predict Internet addiction, but also indirectly predict Internet addiction through meaning in life. Third, reciprocal filial piety played a moderating role between meaning in life and Internet addiction, while authoritarian filial piety did not. For middle school students with low reciprocal filial piety, meaning in life can negatively predict Internet addiction; for those with high reciprocal filial piety, there is no correlation between meaning in life and Internet addiction.

Conclusion

This study reveals the internal mechanism of the relationship between alexithymia and Internet addiction in middle school students, emphasizes the role of positive psychology and family environment, and provides specific evidence and theoretical guidance for preventing Internet addiction in middle school students.

Multiparametric mapping by cardiovascular magnetic resonance imaging in cardiac tumors

BACKGROUND

There is a paucity of quantitative measurements of cardiac tumors and myocardium using parametric mapping techniques. This study aims to explore quantitative characteristics and diagnostic performance of native T1, T2, and extracellular volume (ECV) values of cardiac tumors and left ventricular (LV) myocardium.

METHODS

Patients with suspected cardiac tumors who underwent cardiovascular magnetic resonance (CMR) between November 2013 and March 2021 were prospectively enrolled. The diagnoses of primary benign or malignant tumors were based on pathologic findings if available, comprehensive medical history evaluations, imaging, and long-term follow-up data. Patients with pseudo-tumors, cardiac metastasis, primary cardiac diseases, and prior radiotherapy or chemotherapy were excluded. Multiparametric mapping values were measured on both cardiac tumors and the LV myocardium. Statistical analyses were performed using independent-samples t-test, receiver operating characteristic, and Bland-Altman analyses.

RESULTS

A total of 80 patients diagnosed with benign (n = 54), or primary malignant cardiac tumors (n = 26), and 50 age and sex-matched healthy volunteers were included. Intergroup differences in the T1 and T2 values of cardiac tumors were not significant, however, patients with primary malignant cardiac tumors showed significantly higher mean myocardial T1 values (1360 ± 61.4 ms) compared with patients with benign tumors (1259.7 ± 46.2 ms), and normal controls (1206 ± 44.0 ms, all P < 0.05) at 3 T. Patients with primary malignant cardiac tumors also showed significantly higher mean ECV (34.6 ± 5.2%) compared with patients with benign (30.0 ± 2.5%) tumors, and normal controls (27.3 ± 3.0%, all P < 0.05). For the differentiation between primary malignant and benign cardiac tumors, the mean myocardial native T1 value showed the highest efficacy (AUC: 0.919, cutoff value: 1300 ms) compared with mean ECV (AUC: 0.817) and T2 (AUC: 0.619) values.

CONCLUSION

Native T1 and T2 of cardiac tumors showed high heterogeneity, while myocardial native T1 values in primary malignant cardiac tumors were elevated compared to patients with benign cardiac tumors, which may serve as a new imaging marker for primary malignant cardiac tumors.

Effect of molecular distillation on the anti-inflammatory activity and neurotoxicity of Asarum essential oil

Asarum essential oil (AEO) has been shown to have good pharmacological activities for the anti-inflammatory and analgesic effects, but increasing the dose may cause toxicity. Therefore, we studied the toxic and pharmacodynamic components of AEO by molecular distillation (MD). Anti-inflammatory activity was assessed using RAW264.7 cells. Neurotoxicity was assessed in PC12 cells and the overall toxicity of AEO was evaluated in the mouse acute toxicity assay. The results showed that AEO is primarily composed of safrole, methyl eugenol, and 3,5-dimethoxytoluene. After MD, three fractions were obtained and contained different proportions of volatile compounds relative to the original oil. The heavy fraction had high concentrations of safrole and methyl eugenol, while the light fraction contained high concentrations of α-pinene and β- pinene. The original oil and all three fractions exhibited anti-inflammatory effects, but the light fraction demonstrated more excellent anti-inflammatory activity than the other fractions. Asarum virgin oil and MD products are all neurotoxic. The exposure of PC12 cells to high concentrations of AEO resulted in abnormal nuclei, an increased number of apoptotic cells, increased ROS formation, and decreased SOD levels. Moreover, the results of acute toxicity tests in mice revealed that the light fractions were less toxic than virgin oils and other fractions. In summary, the data suggest that the MD technology enables the enrichment and separation of essential oil components and contributes to the selection of safe concentrations of AEO.

Rambutan-liked Pickering emulsion stabilized by cellulose nanocrystals for enhancing anti-bacterial activity and anti-inflammatory effect of Chimonanthus nitens Oliv. essential oil

Owing to volatility and poor water solubility, the medical application of Chimonanthus nitens Oliv. essential oil (CEO) in the fields of medicine was strictly limited. To tackle this problem, a novel CEO loaded rambutan-liked Pickering emulsion (CEO-RPE) with a spiky surface was effectively designed by coating with carboxymethyl cellulose sodium modified cellulose nanocrystals (CCN) as stabilizer. The effect of CCN concentration on the formation and stabilization of CEO-RPE was investigated. The results showed that CEO-RPE stabilized by 1 % CCN had a smaller droplet size and exhibited a rambutan-liked surface, and was stabilized against concentrated salt and high pH condition due to the steric barrier of CCN that covered in the droplet surface. Subsequently, the antibacterial performance of CEO-RPE was investigated against E. coli, S. aureus, P. aeruginosa, and S. pneumoniae by determining the minimum inhibitory concentration (MIC). The results showed that the CEO-RPE exhibited higher antibacterial activity compared to CEO, which could be attributed to its effective adhesion to the cell membrane of bacteria. In addition, the results of anti-inflammatory experiments showed that CEO-RPE also exhibited strong anti-inflammatory effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats. Therefore, the CCN stabilized rambutan-liked Pickering emulsion seemed to be a promising strategy to increase the antibacterial and anti-inflammatory activity of CEO.

Mucus-penetrating dendritic mesoporous silica nanoparticle loading drug nanocrystal clusters to enhance permeation and intestinal absorption

Multiple gastrointestinal barriers (mucus clearance and epithelium barrier) are the main challenges in the oral administration of nanocarriers. To achieve efficient mucus penetration and epithelial absorption, a novel strategy based on mesoporous silica nanoparticles with dendritic superstructure, hydrophilicity, and nearly neutral-charged modification was designed. The mPEG covalently grafted dendritic mesoporous silica nanoparticles (mPEG-DMSNs) had a particle size of about 200 nm and a loading capacity of up to 50% andrographolide (AG) as a nanocrystal cluster in the mesoporous structure. This dual strategy of combining with the surface topography structure and hydrophilic modification maintained a high mucus permeability and showed an increase in cell absorption. The mPEG-DMSN formulation also exhibited effective transepithelial transport and intestinal tract distribution. The pharmacokinetics study demonstrated that compared with other AG formulations, the andrographolide nanocrystals-loaded mPEG-DMSN (AG@mPEG-DMSN) exhibited much higher bioavailability. Also, AG@mPEG-DMSN could significantly improve the in vitro and in vivo anti-inflammatory efficacy of AG. In summary, mPEG-DMSN offers an interesting strategy to overcome the mucus clearance and epithelium barriers of the gastrointestinal tract.

Sponge-liked Silica Nanoporous Particles for Sustaining Release and Long-Term Antibacterial Activity of Natural Essential Oil

To improve the sustained release and long-term antibacterial activity of Chimonanthus nitens Oliv. essential oil (CEO), novel sponge-liked nanoporous silica particles (SNP) were synthesized via the soft template method, which was employed as a biocompatible carrier to prepare spong-liked nanoporous silica particles loading with CEO (CEO-SNP) through physical adsorption. The structure and properties of the samples were characterized via N2 adsorption/desorption measurements, thermogravimetry (TGA), Fourier transform infrared, SEM and TEM. The result showed that the SNP exhibited an excellent loading capability of CEO up to 76.3%. The thermal stability and release behavior of the CEO were significantly improved via the physical adsorption of the SNP materials. The release profile of CEO was in accordance with the first-order kinetic model, which meant that the release mechanism was drug Fick's diffusion. The antibacterial evaluation results demonstrated that the CEO-SNP exhibited strong antibacterial activity against S. aureus, E. coli and P. aeruginosa. The antibacterial results have shown that the CEO-SNP could destroy the cell structure of bacteria, and result in the generation of oxidative stress and the release of nucleic acid. After storage of 30 d at 25 °C, the CEO-SNP still had the stronger antibacterial activity towards S. aureus, E. coli and P. aeruginosa in comparison with CEO. Therefore, the sponge-like silica nanoporous particles seemed to be a promising carrier for long-term stability and antibacterial delivery of CEO.

A two-ward acute care hospital outbreak of SARS-CoV-2 delta variant including a point-source outbreak associated with the use of a mobile vital signs cart and sub-optimal doffing of personal protective equipment

BACKGROUND

The arrival of the Delta variant of SARS-CoV-2 was associated with increased transmissibility and illness of greater severity. Reports of nosocomial outbreaks of Delta variant COVID-19 in acute care hospitals have been described but control measures varied widely.

AIM

Epidemiological investigation of a linked two-ward COVID-19 Delta variant outbreak was conducted to elucidate its source, risk factors, and control measures.

METHODS

Investigations included epidemiologic analysis, detailed case review serial SARS-CoV-2 reverse transcriptase-polymerase chain reaction (RT-PCR) testing of patients and healthcare workers (HCWs), viral culture, environmental swabbing, HCW-unaware personal protective equipment (PPE) audits, ventilation assessments, and the use of whole genome sequencing (WGS).

FINDINGS

This linked two-ward outbreak resulted in 17 patient and 12 HCW cases, despite an 83% vaccination rate. In this setting, suboptimal adherence and compliance to PPE protocols, suboptimal hand hygiene, multi-bedded rooms, and a contaminated vital signs cart with potential fomite or spread via the hands of HCWs were identified as significant risk factors for nosocomial COVID-19 infection. Sudden onset of symptoms, within 72 h, was observed in 79% of all Ward 2 patients, and 93% of all cases (patients and HCWs) on Ward 2 occurred within one incubation period, consistent with a point-source outbreak. RT-PCR assays showed low cycle threshold (C_T) values, indicating high viral load from environmental swabs including the vital signs cart. WGS results with ≤3 SNP differences between specimens were observed.

CONCLUSION

Outbreaks on both wards settled rapidly, within 3 weeks, using a `back-to-basics' approach without extraordinary measures or changes to standard PPE requirements. Strict adherence to recommended PPE, hand hygiene, education, co-operation from HCWs, including testing and interviews, and additional measures such as limiting movement of patients and staff temporarily were all deemed to have contributed to prompt resolution of the outbreak.

Development of a graphene oxide nanosheet and double-stranded DNA structure based fluorescent "signal off" aptasensor for ochratoxin A detection in malt

A "signal off" fluorescent aptasensor based on graphene oxide (GO) nanosheet and double-stranded DNA structure was fabricated for OTA detection. In the absence of OTA, the aptamer and its complementary DNA (cDNA) formed double-stranded conjugates that could coexist with GO, presenting fluorescence responses. Then, the presented OTA was captured by the aptamers, causing the release of cDNA-FAM probes. The free probes were adsorbed by GO, leading to an OTA concentration-dependent fluorescence quenching through fluorescence resonance energy transfer. Under optimum conditions, the fluorescent aptasensor exhibited outstanding sensitivity with a LOD of 11 pg/mL and a wide dynamic range of 0.04-30 ng/mL. The selectivity of the aptasensor was confirmed against other four mycotoxins, and the feasibility and reliability were verified by determining OTA in the spiked malt samples with satisfactory recovery of 95.50%-112.05%. This aptasensing platform could be adapted to measure other mycotoxins by replacing the aptamer sequences for food safety.

Nanocrystals based mucosal delivery system: Research Advances

Nanocrystal technology is a new way to increase the solubility and bioavailability of poorly soluble drugs. As an intermediate preparation technology, nanocrystals are widely used in drug delivery for oral, venous, percutneous and inhalation administration, which exhibits a broad application prospect. By referring to the domestic anforeign literatures, this paper mainly reviews the preparation methods of nanocrystals for poorly soluble natural products and its application in the mucosal delivery for skin, eye, oral cavity and nasal cavity. This can provide the reference for the research and development of nanocrystal technology in natural product preparations.

To Enhance Mucus Penetration and Lung Absorption of Drug by Inhalable Nanocrystals-In-Microparticles

To effectively achieve the pulmonary delivery for curcumin (CN), novel inhalable mucus-penetrating nanocrystal-based microparticles (INMP) were designed. The D-Tocopherol acid polyethylene glycol 1000 succinate (TPGS) modified CN nanocrystals (CN-NS@TPGS) were prepared by high pressure homogenization and further converted into nanocrystal-based microparticles (CN-INMP@TPGS) using spray-drying. It was demonstrated that CN-NS@TPGS exhibited little interaction with the negatively charged mucin due to a strong electrostatic repulsion effect and PEG hydrophilic chain, and exhibited a much higher penetration ability across the mucus layer compared with poloxamer 407 modified CN-NS (CN-NS@P407) and tween 80 modified CN-NS (CN-NS@TW80). The aerodynamic results demonstrated that the CN-INMP with 10% TPGS acting as the stabilizer presented a high FPF value, indicating excellent deposition in the lung after inhalation administration. Additionally, in vivo bioavailability studies indicated that the AUC(0-t) of CN-INMP@TPGS (2413.18 ± 432.41 µg/L h) were 1.497- and 3.32-fold larger compared with those of CN-INMP@TW80 (1612.35 ± 261.35 µg/L h) and CN-INMP@P407 (3.103 ± 196.81 µg/L h), respectively. These results indicated that the CN-INMP@TPGS were absorbed rapidly after pulmonary administration and resulted in increased systemic absorption. Therefore, the inhalable CN-INMP could significantly improve the bioavailability of CN after inhalation administration. The developed mucus-penetrating nanocrystals-in-microparticles might be regarded as a promising formulation strategy for the pulmonary administration of poorly soluble drugs.

Nanocrystals based pulmonary inhalation delivery system: advance and challenge

Pulmonary inhalation administration is an ideal approach to locally treat lung disease and to achieve systemic administration for other diseases. However, the complex nature of the structural characteristics of the lungs often results in the difficulty in the development of lung inhalation preparations. Nanocrystals technology provides a potential formulation strategy for the pulmonary delivery of poorly soluble drugs, owing to the decreased particle size of drug, which is a potential approach to overcome the physiological barrier existing in the lungs and significantly increased bioavailability of drugs. The pulmonary inhalation administration has attracted considerable attentions in recent years. This review discusses the barriers for pulmonary drug delivery and the recent advance of the nanocrystals in pulmonary inhalation delivery. The presence of nanocrystals opens up new prospects for the development of novel pulmonary delivery system. The particle size control, physical instability, potential cytotoxicity, and clearance mechanism of inhaled nanocrystals based formulations are the major considerations in formulation development.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.